Fig. 3

Association of baseline plasma concentrations of interleukin (IL)-19, IL-20, and IL-24 and total Sharp score (TSS) of radiographic progression in early rheumatoid arthritis (RA) patients and IL-20R1 and IL-22R1 expression on osteoclasts (OCs) and their precursors. a The median baseline values of IL-20 and IL-24 were higher in plasma from patients with TSS progression compared with no progression at 12 and 24 months (see % progressors in Table 1). Data were analyzed using the Mann–Whitney U test. b Co-expression of osteoclast precursor markers and IL-20R1 and IL-22R1 on RA synovial fluid (SF) monocytes. Representative plots of receptor activator of nuclear factor kappa-B (RANK) and CD33 expression on the three monocyte subsets (n = 7). The median percentage of RANK⁺/CD33⁺ cells was increased among IL-20R1⁻/IL-22R1⁺ monocytes compared with IL-20R1⁻/IL-22R1⁻ and IL-20R1⁺/IL-22R1⁻ monocytes. Data were analyzed using the Wilcoxon signed rank test. c Representative confocal microscopy images of IL-20R1 and IL-22R1 staining on tartrate-resistant acid phosphatase positive (TRAP ⁺) cells derived from SFMCs (n = 5). No IL-20R1 expression (20×), and co-expression of TRAP and IL-22R1 in permeabilized cells (20× and 64×, respectively). d Surface expression of IL-22R1 on non-permeabilized cells (20× and 64×, respectively). Boxes indicate the median and interquartile range and whiskers indicate 10–90 percentiles. *P < 0.05, **P < 0.01